Casey A. Greuber, Center for Intelligence Research Analysis and Training
16 March 2010
New Drilling Technologies, Particularly Hydraulic Fracturing,
Likely To Be Utilized At Marcellus Shale Despite Environmental
Issues
Executive Summary:
Relatively new drilling technologies, such as horizontal drilling and hydraulic fracturing
or fracking, will likely be utilized at the Marcellus Shale to extract natural gas from the
high-fracture and organically rich rock formation. Hydraulic fracturing poses several
environmental concerns, including risks to groundwater, drinking water, and disposal of
chemical fracturing fluids, but it is likely none will be substantially significant enough
to deter oil and gas companies from applying the technique to the Marcellus Shale.
Discussion:
Horizontal drilling and hydraulic
fracturing, also known as
hydrofracing, are two terms
occasionally used interchangeably,
however, the drilling processes these
terms imply are quite different.
Horizontal drilling and horizontal
wells have been common practice in
the oil and natural gas industries
since the 1970s, but the concept was
Image illustrating the high-fracture nature of the
first experimented with as early as
shale found at the Marcellus Shale. Source:
1929, according to the United States
http://geology.com/articles/marcellus-shale.shtml
Department of Energy.i The process
involves drilling vertically
downward toward “a gas-bearing rock formation” of some sort, like shale.ii Then,
unique tools curve the well by drilling several thousand feet horizontally, deep within
the rock formation.iii This angle of inclination between the vertical drilling and the
horizontal drilling does not need to reach 90 degrees in order to be considered a
horizontal well and different angles are classified as short-radius, medium-radius, or
long-radius wells.iv This utilizes a majority of the same tools as vertical drilling, aside
from the tools that expand the well horizontally.v Horizontal drilling is particularly
useful for when there are aboveground surface obstructions like roads or airports and
beneath these structures are active natural gas reserves.vi The productivity of
horizontal drilling is nearly 400 percent more than vertical drilling techniques and
only costs 80 percent more overall.vii According to the New York State’s Department
of Environmental Conservation (DEC), horizontal drilling must uphold the same
ethics as vertical drilling in regards to “aquifer protection, fluid containment and
waste handling.”viii
Hydraulic fracturing, also known as hydrofracing or simply fracking, is another
drilling technique entirely. Commercial fracking first began in 1948, but the process
was not perfected until the early 1990s and its success at unconventional gas reserves
was only recognized within the last decade.ix According to the DEC, “The majority of
wells in the Marcellus Shale will be hydraulically fractured.”x Hydraulic fracturing or
frac jobs are particularly appealing to areas like the Marcellus Shale because shale is
described as a “tight” rock that few other drilling techniques are successful at
obtaining sizeable quantities of gas from.xi As a result, in nine out of ten natural gas
wells, hydraulic fracturing is the method utilized.xii The fracking process involves
large volumes of water, likely exceeding one million gallons of water per well in the
Marcellus Shale.xiii The technology also requires large amounts of propping material
or proppants, which open fractures so more natural gas escapes the cracks.xiv The
process involves pumping a highly pressurized mix of water and silica sand, or some
other proppant, down a well to create fractures in gas-bearing formations.xv The fluid
also contains other compounds designed to enhance the effectiveness of the fracturing
process which can be harmful to humans and wildlife, like friction reducers, biocides,
surfactants, scale inhibitors and even hydrochloric acid.xvi Approximately 20 to 40
percent of the water containing chemical compounds may not be extracted with the
natural gas and remains in the ground.xvii Both drilling technologies are ultimately
designed to reduce overall drilling and completion costs, despite expensive initial
investments.xviii
Chemical composition of the fluid utilized in hydraulic fracturing to increase the efficiency of
the process. Source: http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf
A paper that was presented in 2008 to the Ground Water Protection Council on
Hydraulic Fracturing Considerations for Natural Gas Wells of the Marcellus Shale
addressed key issues like risks to groundwater, as well as drinking water, and
chemical-laden fracturing fluids.xix Environmentalists are concerned that modern
drilling practices could lead to corrosion of the shale, which protects groundwater
below it, and gas or chemical fluids may discharge into a potential drinking water
supply.xx Any spills of fracturing fluid on the surface could also run off and
contaminate current drinking water supplies.xxi However, as of 2002, the
Environmental Protection Agency (EPA) concluded the safe practice of hydraulic
fracturing “does not pose a risk to drinking water.”xxii The difficultly disposing of
chemical wastewater created by the fracking process is another environmental
concern, involving long-term storage in rural areas or refinement at water treatment
facilities.xxiii A large number of drilling companies use slickwater fluids where water
is the main component, but other additives are also mixed into the water to perform
specific functions, such as preventing the growth of microorganisms or widening
fractures.xxiv Service companies are reportedly attempting to create “more
environmentally friendly fluids” but, as of now, the chemical compounds in the
fracturing fluid maintain an issue of concern.xxv
Diagram illustrating how the process of hydraulic fracturing, also known as hydrofracing, is carried
out from the delivery of the water to the piping of the product to natural gas markets. Source:
http://www.propublica.org/special/hydraulic-fracturing-national
Analytic Confidence:
Analytic confidence for this assessment is medium. Source reliability ranges from
medium to high and, although there is no conflict among sources, the analyst had low
expertise and worked alone. The analyst did not utilize structured analytic methods, the
subject was minimally complex, and there was an appropriate deadline for collection
and analysis to be conducted by.
For questions or comments, please contact the author:
Email: cgreub97@mercyhurst.edu
Tel. #: 440-429-2085
i
http://www.spe.org/spe-app/spe/jpt/1999/07/frontiers_horiz_multilateral.htm (High)
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
iii
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
iv
http://www.spe.org/spe-app/spe/jpt/1999/07/frontiers_horiz_multilateral.htm (High)
v
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
vi
http://www.horizontaldrilling.org/ (Medium)
vii
http://www.naturalgas.org/naturalgas/extraction_directional.asp (Medium)
viii
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
ix
http://www.energyindepth.org/in-depth/frac-in-depth/history-of-hf/ (Medium)
x
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
xi
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
xii
http://www.propublica.org/special/hydraulic-fracturing-national (Medium)
xiii
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
xiv
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
xv
http://www.dec.ny.gov/energy/46288.html#horizontal (High)
xvi
http://www.earthworksaction.org/pubs/OGAPMarcellusShaleReport-6-12-08.pdf
(High)
xvii
http://www.earthworksaction.org/FracingDetails.cfm (Medium)
xviii
http://www.spe.org/spe-app/spe/jpt/1999/07/frontiers_horiz_multilateral.htm (High)
xix
http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf (High)
xx
http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf (High)
xxi
http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf (High)
xxii
http://www.energyindepth.org/in-depth/frac-in-depth/history-of-hf/ (Medium)
xxiii
http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf (High)
xxiv
http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf (High)
xxv
http://www.dec.ny.gov/docs/materials_minerals_pdf/GWPCMarcellus.pdf (High)
ii